The invention relates to a keyboard comprising at least one flap forming a key, and a contact point, the flap being pressed against the contact point when depressed from above, and rising back after the depressing.
Further, the invention relates to a method for forming a keyboard.
U.S. Pat. No. 4,480,937 discloses a keyboard having a metal sheet provided with leaf springs. The end of a leaf spring is flexible and is depressed with a plunger at the tip of which there is typically a key top. When the plunger is depressed, the contact cantilevers formed on the sides of the leaf spring get into contact with a contact surface, and after the depressing the leaf spring raises the plunger into the upper position. Such a keyboard structure is complex and takes a lot of space, and in addition, it is rather difficult to manufacture.
U.S. Pat. No. 4,160,886 discloses a keyboard formed in a plastic sheet in such a way that the plastic sheet comprises key projections extending upwards and a protuberance extending downwards towards a contact surface. The keys are partially cut off the plastic sheet in such a way that they are attached to the plastic sheet only by one edge. A separate dome spring is arranged below each key, whereby the dome spring buckles downwards when a key is depressed, contacting the contact surface, and after the depressing, the dome spring returns the key into the upper position. A mask provided with openings for the keys is arranged upon the plastic sheet. The structure of the keyboard is complex and contains several layers. Therefore, the keyboard is rather difficult to manufacture. Further, the space available for the key graphics on the upper surface of the keys is relatively small.